1. Field of the Invention
The present invention relates to a heat exchanger that has tubes, header pipes, an inlet connector block and an outlet connector block.
2. Description of the Related Art
Two heat exchangers are disclosed in Japanese Patent Provisional Publication No. 11-325784. As shown in FIG. 1, the former heat exchanger 50 is comprised of tubes 51, corrugated fins 52, header pipes 53, 53, an inlet connector block 54 and an outlet connector block 55. The plural tubes 51 are disposed in spaced relationship with respect to one another. The plural corrugated fins 52 are disposed between adjacent tubes 51. The header pipes 53, 53 are connected to both ends of each tube 51. The inlet connector block 54 is fixedly secured to one header pipe 53. The outlet connector block 55 is fixedly secured to the other header pipe 53.
First fluid (coolant) enters from the inlet connector tube 54 and flows through a given flow path including one header pipe 53, the plural tubes 51, the other header pipe 53 in this order. First fluid efficiently heat-exchanges with second fluid flowing outside of the tubes.
Next, a connecting structure between one header pipe 53 and the inlet connector block 54 of the heat exchanger 50 is described. As shown in FIG. 2, a partition wall 56 is formed in the header pipe 53 along a longitudinal direction thereof, dividing an interior of the header pipe 53 into pipe-inside flow-through bores 57a, 57b. The partition wall 56 provides an increased compressive strength. Also, an internal communicating bore 59 is formed in the partition wall 56 to allow the pipe-inside flow-through bores 57a, 57b to communicate with one another. Formed on an outer peripheral surface of the header pipe 53 is a block connector bore 58 that is open to the pipe-inside flow-through bore 57a. A distal end of an in-pipe 54a of the inlet connector block 54 is inserted to the block connector bore 58 and fixedly connected thereto.
First fluid flows from the inlet connector block 54 into the pipe-inside flow-through bore 57a and then enters to the pipe-inside flow-through bore 57b through the internal communicating bore 59. With such a structure, first fluid is distributed and supplied from the inlet connector block 54 to the pipe-inside flow-through bores 57a, 57b formed inside the header pipe 53. A flow distribution ratio of first fluid to be distributed to the pipe-inside flow-through bores 57a, 57b varies depending upon a ratio between a diameter A of the block connector bore 58 and a diameter B of the internal communicating bore 59. Also, the other header pipe 53 and the outlet connector block 55 have the same connecting mechanism as that of one header pipe 53 and the inlet connector block 54.
As the latter heat exchanger, as shown in FIG. 3, the latter heat exchanger 60 is comprised of tubes 61, corrugated fins 62, header pipes 63, 63, an inlet connector block 64 and an outlet connector block 65.
The plural tubes 61 are disposed in spaced relationship with respect to one another. The plural corrugated fins 62 are disposed between adjacent tubes 61. The header pipes 63, 63 are connected to both ends of each tube 61. The inlet connector block 64 is fixedly secured to one header pipe 63. The outlet connector block 65 is fixedly secured to the other header pipe 63.
Next, a connecting structure between one header pipe 63 and the inlet connector block 64 of the heat exchanger 50 in the heat exchanger 60 is described. As shown in FIG. 4B, a partition wall 66 is formed in the header pipe 63 along a longitudinal direction thereof, dividing an interior of the header pipe 63 into pipe-inside flow-through bores 67a, 67b. The partition wall 66 provides an increased compressive strength. As shown in FIG. 4C, an outer peripheral wall of the header pipe 63 is formed with block connector bores 68a, 68b that are open to the pipe-inside flow-through bores 67a, 67b, respectively. As shown in FIG. 4A, the inlet connector block 64 has branch pipes 64b, 64c each of which has one end connected to an in-pipe 64a. The branch pipes 64b, 64c are inserted to and fixed to the block connector bores 68a, 68b, respectively.
First fluid flows from the branch pipes 64b, 64c of the inlet connector block 64 into the pipe-inside flow-through bores 67a, 67b, respectively. With such a structure, first fluid is distributed and supplied from the inlet connector block 64 to the pipe-inside flow-through bores 67a, 67b formed inside the header pipe 63. A flow distribution ratio of first fluid to be distributed to the pipe-inside through-bores 67a, 67b varies depending upon an internal diameter ratio between the branch pipes 64b, 64c. Also, the other header pipe 63 and the outlet connector block 65 have the same connecting mechanism as that of one header pipe 63 and the inlet connector block 64.
The former heat exchanger has the following problems: With the heat exchanger 50, since the internal communicating bore 59 is formed inside the header pipe 53, it becomes hard to conduct work for machining the heat exchanger 50. Also, in order to vary the flow distribution ratio of first fluid to be distributed to the pipe-inside flow-through bores 57a, 57b, there is a need for changing the diameter A of the block connector bore 58 and the diameter B of the internal communicating bore 59, and it becomes hard to conduct work for machining the heat exchanger 50.
The latter heat exchanger has the following problems: With the heat exchanger 60, since the block connector bores 68a, 68b are formed on the outer peripheral wall of the header pipe 63, it becomes hard to conduct work for machining the heat exchanger 60. Also, in order to vary the flow distribution ratio of first fluid to be distributed to the pipe-inside flow-through bores 67a, 67b, there is a need for changing the internal diameter ratio between the block connector bores 58a, 58b and it becomes hard to conduct work for machining the heat exchanger 60.